Toronto police have arrested six people following a series of marijuana dispensary robberies dating back to mid-March.

Despite the "good news" of the arrests, Mark Pugash, spokesperson for the Toronto Police Service, said police investigations were hampered by a lack of cooperation from "some owners and victims" involved.

By not working with police, Pugash said dispensary owners are "endangering not only their customers, but they're also endangering their staff."

He also shared concerns that additional robberies are taking place that are not being reported to police.

There's been an "alarming increase in violent armed robberies in dispensaries" and people who don't come forward to police are "enabling those sorts of people to continue committing those sorts of crimes," said Pugash.

He also reiterated that "there is no grey area in the law, dispensaries are absolutely against the law, the law is black and white."

Police allege that between Friday, March 17 and Friday, April 7, four dispensaries were held up at gunpoint. The robberies took place at:

- 1605 Dundas Street West.

- 350 Broadview Avenue.

- 1363 Dundas Street West.

- 333 Spadina Avenue.

The suspects, wearing disguises, took control of the employees and stole marijuana and cash.

Pugash wouldn't say whether the group is affiliated with organized crime, but did highlight that four of the suspects arrested are between 15 and 17-years-old.

Convenience store also robbed

Police believe two of the males involved in the dispensary robberies were also involved in a convenience store robbery on March 15, along with another yet-to-be-identified male. The suspects entered the store in the Rexdale Boulevard and Islington Avenue area, tackled the employee and stole cash and lottery tickets.

A 20-year-old man, 24-year-old woman and four boys aged between 15 and 17 were arrested and charged on April 13.

Police are still looking for one suspect and ask anyone with information to contact them or Crime Stoppers.